Catalytic device



June 11, 1 957 o NM. RErrzL Erm.

CATALYTIC DEVICE 2 Sheets-Sheet 1 Filed Ja'n. 27. 1954 Il. ..IIIJ lllIlll-.lL-Ilo oo oww non o wooo o ooo co :ooo oo wooo ooo ovvooo oooo ovo 000 D MN N Y INVENTQRS. NlCOLAS M. REITZEL .8| BERTON KAROL ATTO RNEY June 1l, 1957 N. M. RElTzEL ETAL 2,795,488

cATALYTIc DEVICE Filed Jan. 27. 1954 2 Sheets-Sheet 2 INVENTORS. NICOLASM. REITZEL 8| BERTON .KAROL ATTOR N EY CATALYTHC DEVICE Nicolas M.Reiner, Sanford, and Benen Karol, Philadelphia, Pa., assignors toOxy-Catalyst, Inc., a corporation of Pennsylvania Application January27, 1954, Serial No. 406,442

9 Claims. (Cl. 23m-288) Our invention relates to catalytic apparatus ofthe general type disclosed in the copending application of Eugene I.Houdry, Serial Number 318,382 for Catalytic Apparatus, led November 3,1952. ln many respects our invention provides improvements to the basicHoudry apparatus while other aspects of our invention are applicable tocatalytic mufiers in general.

In the aforementioned Houdry application there is disclosed a catalyticapparatus for attachment to the exhaust manifold of an internalcombustion engine for oxidizing toxic and obnoxious components of theexhaust gases therefrom. Generally speaking, this Houdry apparatuscomprises a housing, closed at the ends by end plates, which contains arelatively thin bed of catalytic material which bed is confined betweenforaminous trays. The catalyst containing trays are mounted on beamscarried in turn by the housing in such manner as to permit thermalexpansion and contraction of the beams independently of the housing.

It is one of the objects of the present invention to provide an improvedbeam construction of the general type disclosed in the aforementionedHoudry application.

It is a further object of the present invention to provide an improvedarrangement for the catalyst-containing foraminous trays which willafford improved efficiency in the operation of the muffler.

It is further object of the invention to provide an improved and moreeconomical construction for the end plates affording easier access tothe interior of the muffler. Y Further objects of the invention will beapparent from the following description and from the accompanyingdrawings in which:

Fig. 1 is a cross-sectional side view, with parts broken away, of anembodiment of the invention taken along the lines 1-1 of Fig. 2.

Pig. 2 is a cross-sectional view taken at right angles to Fig. l alongthe lines 2 2 of Fig. l.

. Fig. 3 is a fragmental plan view of a tray of a type usable in ourapparatus.

Fig. 4 is a plan view of an end plate clamping member.

Fig. 5 is a view, similar to Fig. 3 showing a modified form of tray.

Fig. 6 is an exploded perspective view showing a mounting member, aportion of a beam, and a connecting pin.

l Fig. 7 is a fragmentary sectional view showing details of therelationship between a housing shell and end plat of the preferredembodiment.

Referring to Fig. l, our apparatus comprises a housing, indicatedgenerally by reference numeral 1, catalyst containing means and mountingmeans for the catalyst containing means.

' The housing is composed of a shell member 2, end plates 3 and clampingmembers 8, also shown in Fig. V4. The shell is preferably, but notnecessarily, of cylindrical shape and is provided with a plurality ofaligned openings 5 which are closed by plugs 6 as shown in Fig. 2'.These openings permit recharging of the catalyst bed from the outside of.the housing without disassembly ate-nt 2,795,488 `Pau'tented Junell,1,957

. 2 i. Q; thereof. In thev preferred embodiment of ourV invention theplugs are provided in the form of expansible rivets which cooperate withgaskets 6a to seal the openings but any alternative type of plug, suchas a threaded plug, may be employed. The edges of the shell are flaredto provide radially extending flanges 4. The end plates 3 conform to thecross sectional shape of the shell and are provided with peripheralportions in the form of offset flanges 7 which abut the shell anges 4. AU-shaped split clamping member 8 (Figs. 1 and 4) is provided for eachend plateto straddle the end plate and shell ilanges and' hold them inairtight relationship which may be enhanced by the interposition ofgasketing 9, as clearly shown in Fig.V 7. An adjustable connection is-provided to connect the two ends of the clamping member across thesplit portion thereof which in the embodiment shown comprises a machinescrew 10 and nut 11 which cooperate `with perforate e'ars 12 on the endsof the clamping member. Other adjustable connections might be providedin place of the screw and nut. The faces of the end plates are providedwith inlet and outlet pipes 13 and 14 through which exhaust gases passinto and out of the apparatus. The inlet pipe 13 is preceded in theexhaust line by an air inspirator 13a operating on the venturiprinciple. As shown in the drawing the inspirator comprises a afrustroconical section 14 diverging as it approaches the end plate.Beyond the frustro-conical portion 14 a second frustroconical portion14a is provided which terminates in a ange 15 secured to a second flange15a provided on exhaust pipe 16. The exhaust pipe terminates in a nozzle17. An air inlet 18 provided with a filter 18a completes this inspiratorstructure.

The disclosed housing is simple to manufacture and requires virtually noexpensive machining operations. The parts can be formed from standardgages of steel sheet and assembled with a minimum of effort. Theintertting flanges 4, 7 on the shell 2 and end plates 3 provide thenecessary airtight relationship of these parts while permittingdisassembly of the apparatus for repairs or servicing in a minimum oftime.

The catalyst containing means of the disclosed embodiment of theinvention comprises a pair of opposed foraminous trays which enclose acatalyst bed receiving space 19. Each of these trays is composed of aplurality of tray sections 2i) described in detail below. The traysextend longitudinally and transversely of the housing a distancesubstantially equal to but less than the length and width of thehousing. The clearance thus remaining, shown in Figs. 1 and 2 andindicated by reference numeral 21, between the edges of the trays andthe internal walls4 of the housing is suflicient to permit the trays tothermally expand independently of the housing but this clearance is notso large as to permit catalyst particles from the bed to escape from thespace between the trays. The'sections on the ends of each of the traysoverlap channel-shaped sealing members 22 which are welded or otherwisesecured to the internal face of each end plate 3. Thus catalystparticles are restricted from escaping from the cata-V 0.062 indiameter, which are arranged in rows with approximately 74 holes persquare inch of tray surface." For purposes of illustration, only a fewof these holes are shown in Figs. 3 and 5. Stiffening ribs 23 (Figs. l,3 and '5) are formed in the trays preferably by a stamping operationwhich produces channels on one side ofthe tray and protrusions on theother side; thereof as shown'- in Fig. 1. These ribs may extend onlytransversely across the tray sections, as shown in Fig. 3, ortransversely and longitudinally on the trays to form a Waie pattern, asshown in Fig. 5. The tray sectionV edges which extend transversely areflanged, as at 25 in order to further stiien these members.

The tray sections 20 are desirably of stainless steel or other hightemperature alloy because of the fact that they must withstand operatingtemperatures in the range of 500 F. to 1800 Pertorations are providedover the entire surface area ot the trays for the purpose of permittingthe passage of exhaust gases therethrough. The tray sections aredesirably of thin gage material because it is important to minimize theuse of relatively expensive stainless steel, because of weightconsiderations, and finally because of the fact that the formation ofclosely spaced perforations in stainless steel is economically feasibleonly with thin stock. The ribs 23 are provided because of the fact thatsuch thin stock` is inherently ilexible and ilexible trays in our devicewould be inadmissible since they would permit the escape of catalystparticles from the bed.

Divider plates 26, Figs. l and 2, are secured as by welding to theflanges of these trays, for the purpose of dividing the catalyst bedinto a plurality of compartments. The utility of these dividers stemsfrom the fact that in a compartmented catalyst bed, as opposed to anuncompartmented bed, the catalyst particles have less tendency to packin one end of the bed if the apparatus is tilted from its horizontalposition. The use of divider means to compartment the catalyst bed ismore fully described in application Serial Number 438,423, tiled June22, 1954, by Eugene I. Houdry for Catalytic Exhaust Cleaner Purier.

The mounting means for the trays comprises elongated channel shapedbeams 27 aihxed to the internal Wall of the shell 2 by means of U-shapedbeam supports or mounting members 28. The tray sections 20 are Welded orotherwise secured to the underside of the base 29 of each beam, spotwelds 3d being provided in the disclosed embodiment of our invention.The beams are notched as at 31 and 32, the notches extending across thebase 29 of each beam and up the sides 33 thereof. These notches receivethe protrusions formed by the ribs 23 and the end flanges Z5 as shown inFig. l so that the protrusions project away from, and not into, thecatalyst bed. The importance of this feature Will be discussed below. Aswill also be explained below the relationship of the notches to the ribprotrnsions and the anges expedites the assembly of the tray sections tothe beams.

The channel shaped beams of our invention can conveniently be formed bymerely punching openings in a piece of flat sheet stock and subsequentlybending the at sheet into the desired channel shape. 'The openings forslots 34 (described below) and the notches 31, 32 can be punched in asingle punching operation. Thereafter it is only necessary to bend thepunched blank to form the finished notched and slotted beam. This is animportant feature of our invention and affords many advantages overother types of construction, such as that shown in the aforementionedHoudry application, Serial Number 318,382, in that expensive machiningoperations are completely eliminated and the resulting structure is bothstrong and light in weight.

The U-shaped beam supports or mounting lmembers 28, shown in Figs. 1, 2,and 6, extend within and between the sides of the channel-shaped beamand are connected thereto by means of a pin-slot or other lost `motionconnection. in the preferred embodiment of the invention each beam issupported by means of two such hangers with slots 34 being provided inthe sides of the beams 27 and punched holes 35 being provided inthesides of the beam supports. A pin, in the form of a tubular rivet 40extends through these slots and holes to hold the parts in assembledrelation whilst permitting longitudinal movement of the beam under theinfluence of thermal expansion. This pin, which is under a tensionalforce, tends to draw the sides 33 of the beam inwardly toward each otherinto a snug engagement with the supports 28 but the relationship of theparts is not so tight as to prevent thermal expansion and contraction ofthe parts independently of each other. lt is understood that the numberof beam supports provided for each beam is not critical. One elongatedsupport would be suhcient to mount each beam or more than two supportsmight be provided for each beam.

The open ends of the U-shaped mounting members or beam supports areprovided with oppositely extending flanges 36, Fig. 6, having surfacesshaped to conform to the internal surface of the housing. These llangesare rigidly secured to the shell member by bolting in the preferredembodiment of our invention. To this en d a nut pocket 37 (Fig. 2) iswelded to the underside of each iange 36 in alignment with a boltreceiving hole 38 in the ange. Alternatively the U-shaped supportslmight be directly welded to the shell member.

The U-shaped beam supports 28, like the channel shaped beams 27, can beconveniently formed by a series of inexpensive punching and bendingsteps.

Referring again to the catalyst containing trays it will be noted thatthey enclose between them a relatively thin bed of catalyst particles.ln a catalytic apparatus of the type disclosed herein the thickness ordepth of this catalytic bed is an important consideration from thestandpoint particularly of not imposing a high back pressure on theinternal combustion engine thus impairing this efficiency. Thisconsideration calls for a relatively shallow bed of relatively extensivesurface area. Because of the necessary shallowness of the bed,maintaining uniforrnity of bed thickness becomes an importantconsideration. Even relatively slight variations in bed thickness willlead to undesirable channeling of exhaust gases through the shallowerportions and corresponding loss of efficiency in destroying obnoxiousoxidizable components. With respect to this question of maintaininguniformity of bed thickness, the arrangement of the ribbed foraminoustrays as disclosed herein is an important feature of the invention. ltwill be noted that the ribs project away from rather than into thecatalyst bed and are accommodated by the notches 31 provided in thebeams 27. Through this arrangement, constriction of the catalyst bedwhich would otherwise occur at the points where the ribs project intoit, as disclosed in copending application Serial Number 318,382, isobviated. This constriction is particularly serious where the ribs arein alignment with one another.

An additional advantage of this arrangement of ribbed trays and notchedbeams is that the structural relationship between the ribs and thenotches simplifies the assembly of the tray sections to the beams. Thisis evident from Fig. 1 where the ribs are shown protruding into thenotches 31 and the flanges are shown in notches 32. To position a traysection on a beam preparatory to spot welding, it is only necessary tolay the tray on the beam, with the rib protrusions downward and alignthe tray section axially along the beam with the rib protrusions seatedin the notches 31 and the iianges projecting into the notches 32. Withthe rrib protrusions thus seated the end anges Z5 of adjacent trays willbe properly spaced from each other in the notches 32 and the surface ofthe tray will be Hush against the underside 29 of the beam 27. Thespacing between adjacent anges 2S must be held within relatively closedimensional tolerances since this spacing must be sutliciently wide topermit longitudinal expansion of the sections and suciently narrow topreclude the escape of catalyst particles from the bed. After the traysection is positioned on the beam the spot welds 30 can be made by wellknown practice.

In the operation of the device, exhaust gases from the' internalcombustion engine pass through the exhaust pipe 16 and are intermixedwith fresh air by the inspirator 13a. The addition of fresh air to thegases is necessary in order to provide the necessary excess oxygen toassure substantially complete oxidation of the carbon monoxide andhydrocarbons contained in the exhaust. 'Ihe mixture of exhaust gases andair then passes into the upper portion of the muffler designated by theletter A. From there the gases flow through the catalyst bed and intothe lower zone B of the mufer from which they pass through the outletpipe 14. While passing through the catalyst bed the hydrocarbons andcarbon monoxide are oxidized to produce carbon dioxide and water vapor.

, Any suitable oxidation catalyst, capable of operation at temperaturesin the range of about 500 F. to 1800 F. may be employed. It isunderstood, of course, that the invention is not limited to anyparticular kind of catalyst. One type of catalyst which has been foundto be particularly suitable, however, consists of pellets of activatedalumina Ms to ll in diameter, and of about the same length, impregnatedwith about 0.4% by weight of platinum. The platinum impregnation may beaccomplished by immersing the pellets in a 1% solution of platinumchloride for about minutes, draining, and then decomposing the platinumchloride by heat at about 1l00 F. to leave the metallic platinumdeposited on the alumina. Preferably the space between the foraminoustrays is not lled to the limit of its capacity With catalytic particles.The space between the foraminous trays must not be packed tightly withcatalyst particles since the tightly packed particles would tend to becrushed by each other as the catalytic bed is heated and the particlesexpand. On the other hand, the space between the trays must be filledsufficiently to avoid uneven bed depth due to shifting of the catalystparticles as the apparatus is tilted from a horizontal position. Suchunevenness in the bed depth would have the undesirable result thatexhaust gases would preferentially pass through the thinner bed portionsand fail to be fully oxidized.

It is thus apparent that we have disclosed a catalytic muier structurein which thermal expansion and contraction of the various parts ispermitted and which also precludes the possibility of by-pass orchannelling of exhaust gases around the catalytic bed. At the same timeour device is amenable to economic and expeditious manufacturingprocesses. While we have disclosed the preferred embodiment of ourinvention, it may be practiced in other forms and adaptations which fallwithin the purview of the appended claims.

We claim:

1. Catalytic apparatus suitable for attachment to the exhaust outlet ofan internal combustion engine for oxidizing toxic and obnoxiouscomponents of the exhaust gases therefrom comprising an elongatedhousing, catalyst containing means in said housing and rigid supportingmeans for said catalyst containing means, said rigid supporting meanscomprising elongated channel shaped beams extending longitudinallywithin said housing, said catalyst containing means being supported bythe underside of the base of said beams, means mounting said channelshaped beams within said housing comprising members rigidly secured tosaid housing and extending within and between the sides of said channelshaped beams, and a connection between each of said members and itsassociated beam, said connection permitting expansion and contraction ofeach of said beams independently of said member and said housing.

2. Catalytic apparatus suitable for attachment to the exhaust outlet ofan internal combustion engine for oxidizing toxic and obnoxiouscomponents of the exhaust gases therefrom comprising an elongatedhousing, catalyst containing means in said housing and rigid supportingmeans for said catalyst containing means, said rigid supporting meanscomprising elongated channel shaped beams extending longitudinallywithin said housing, said catalyst containing means being supported bythe underside -of the `base of said beams, `U-shaped mounting memberssecured at their open ends to said housing, the closed end of each ofsaid U-shaped mounting members extend.- ing within and betweenthe sidesof one of said channel shaped beams, and a pin-slot connection betweeneach of said U-shaped members and its associated beam, said pin-slotconnection permitting expansion and contraction of each of said beamsindependently of its associated mounting member and said housing.

3. Catalytic apparatus suitable for attachment to the exhaust outlet ofan internal combustion engine for oxidizing toxic and obnoxiouscomponents of the exhaust gases therefrom comprising an elongatedhousing, catalyst containing means in said housing, rigid supportingmeans for said catalyst containing means comprising elonf gated beams insaid housing extending longitudinally thereof, said catalyst containingmeans comprising a plurality of fo'raminous trays extendinglongitudinally and laterally of said housing a distance substantiallyequal to the length and width of said housing, each of said trays beingprovided with transverse stitfening ribs forming protrusions on thesurfaces of said trays, said trays being in opposed face-to-facerelationship to define therebe: tween a space for receiving a relativelythin bed of catalyst particles, said beams being provided with notcheson the tray supporting surfaces thereof, each of said trays beingsupported by one of said beams with the notches of said beams receivingthe ribs of said trays whereby said ribs protrude into said notches andnot into said catalyst bed whereby a substantially uniform velocity ofgases through said catalyst bed is obtained throughout the area of saidbed.

4. Catalytic apparatus suitable for attachment to the exhaust outlet ofan internal combustion engine for oxidizing toxic and obnoxious`components of the exhaust gases therefrom comprising anelongatedhousing, catalyst containing means in said housing, rigid supportingmeans for said catalyst containing means comprising elongated channelshaped beams in said housing extending longitudinally thereof, meansmounting said channel shaped beams within said housing comprisingmembers rigidly secured to said housing and extending within and betweenthe sides of said channel shaped beams, a connection between each ofsaid members and its associated beam, said connection permittingexpansion and contraction of each of said beams independently of saidmember and' said housing, said catalyst containing means comprisingforaminous trays extending longitudinally and laterally of said housinga distance substantially equal to the length and width of said housing,each of said trays being provided with transverse stiffening ribsforming protrusions on one side of the tray and channels on the otherside thereof, said trays being in opposed face-to-face relationship todefine therebetween a space for receiving a relatively thin bed ofcatalyst particles, said channel shaped beams being provided withnotches extending from the base of the beam along each side thereof,each of said trays being supported by the underside of the base of oneof said beams with the notches of said channel-shaped beams receivingthe ribs of said trays whereby said ribs protrude into said notches andnot into said catalyst bed whereby a substantially uniform Velocity ofgases through said catalyst bed is obtained throughout the area of saidbed.

5. Catalytic apparatus suitable for attachment to the exhaust outlet ofan internal combustion engine for oxidizing toxic and obnoxiouscomponents of the exhaust gases therefrom comprising a housing, catalystcontaining means in said housing, supporting means for said catalystcontaining means, said catalyst containing means comprising foraminoustrays extending longitudinally and laterally of said housing, said traysbeing in opposed faceto-face relationship to define therebetween a spacefor receiving a relatively thin bed of catalyst particles, said traysbeing provided with stifening ribs pressed into said trays and formingprotrusions on one'side of the tray and channels on the other sidethereof, said ribs projecting away from and notl into the space betweensaid trays whereby a substantially uniform ow of gases through said thincatalyst bed is obtained throughout the area of said bed.

6. Catalytic apparatus suitable for attachment to the exhaust outlet ofan internal combustion engine for oxidizing toxic and obnoxiouscomponents of the exhaust gases therefrom'comprising a housing, catalystcontaining means in said housing, supporting means for said catalystcontaining means, said catalyst containing means comprising a pluralityof foraminous trays extending longitudinally and laterally of saidhousing, each of said trays being provided with stitening ribs pressedinto said trays and forming protrusions on one side of the tray andchannels on the other side thereof, said trays being in opposedface-to-face relationship to deiine therebetween a spaceV for receivinga relatively thin bed of catalyst particles, the corresponding ribs ofopposed trays beingV in alignment with one another, said ribs projectingaway from, and not into, the space between said trays whereby asubstantially uniform flow of gases is obtained throughout the area ofsaid bed. i

7. Catalytic apparatus suitable for attachment to the exhaust outlet ofan rinternal combustion engine for oxidizing toxic andV obnoxiouscomponents of the exhaust gases therefrom comprising a housing, catalystcontaining means in said housing, rigid supporting means for saidcatalyst containing means, said rigid supporting means being carried bysaid housing in such manner as to permit expansion and contractionthereof independently of said housing, said catalyst containing meanscomprising foraminous trays divided into a plurality of sectionsextending longitudinally and laterally of said housing a distancesubstantially equal to the length and width thereof, each of said traysections being provided with stiffening ribs pressed into said traysections and forming protrusions on one side of the tray and channels onthe other side thereof, said trays being in opposed face-tofacerelationship to define therebetween a space for receiving a relativelythin bed of catalyst particles, the corresponding ribs of opposed traysections being in alignment with one another, said ribs projecting awayfrom, and not into, the space between` said tray sections whereby asubstantially uniform dow of gases is obtained throughout the area ofsaid bed. Y

8. Catalytic apparatus suitable for attachment to the exhaust outlet ofan internal'combustio'n engine for oxidizing toxic and obnoxiouscomponents of the exhaust gases therefrom comprising a housing, catalystcontaining means in said housing, rigid supporting means for saidcatalyst containing means, said rigid supporting means being carried bysaid housing in such manner as toV permit expansion and contractionthereof independently of said housing, said housing comprising anelongated open ended shell provided with flanges at the open endsthereof, end plates closing the open ends of said shell, said end platesbeing provided with peripheral portions complementary to and abuttingsaid tlanges, and Yclamping means clamping said end plates to saidshell.

9. Catalytic apparatus suitable for attachment to the exhaust outlet ofan internal combustion engine for oxidizing toxic and obnoxiouscomponents of the exhaust gases .therefrom comprising a housing,catalyst containing means in said housing, rigid supporting means forsaid catalyst containing means, said rigid supporting means beingcarried by said housing in such manner as to permit expansion andcontraction thereof independently of said housing, said housingcomprising an elongated open ended shell provided with flanges at theopen ends thereof, end plates closing the open ends of said shell, saidend plates being provided with peripheral portions complementary to andabutting said flanges, clamping means clamping said end plates to saidshell comprising split clamping members of U-shaped cross sectiondisposed over the peripheral portions of said endplates and the anges ofsaid shell, and adjustable connecting means connecting the ends of saidsplit clamping member across the split portion thereof.

References Cited in the le of this patent UNITED STATES PATENTS1,867,325 Neville July 12, 1932 2,004,865 Grison June 11, 1935 FOREIGNPATENTS 312,200 Great Britain May 21, 1929

2. CATALYTIC APPARATUS SUITABLE FOR ATTACHMENT TO THE EXHAUST OUTLET OFAN INTERNAL COMBUSTION ENGINE OF OXIDIZING TOXIC AND OBNOXIOUSCOMPONENTS OF THE EXHAUST GASES THEREFROM COMPRISING AN ELONGATEDHOUSING, CATALYST CONTAINING MEANS IN SAID HOUSING AND RIGID SUPPORTINGMEANS FOR SAID CATALYST CONTAINING MEANS, SAID RIGID SUPPORTING MEANSCOMPRISING ELONGATED CHANNEL SHAPED BEAMS EXTENDING LONGITUDINALLYWITHIN SAID HOUSING, SAID CATALYST CONTAINING MEANS BEING SUPPORTED BYTHE UNDERSIDE OF THE BASE OF SAID BEAMS, U-SHAPED MOUNTING MEMBERSSECURED AT THEIR OPEN ENDS TO SAID HOUSING, THE CLOSED END OF EACH OFSAID U-SHAPED MOUNTING MEMBERS EXTENDING WITHIN AND BETWEEN THE SIDES OFONE OF SAID CHANNEL SHAPED BEAMS, AND A PIN-SLOT CONNECTION BETWEEN EACHOF SAID U-SHAPED MEMBERS AND ITS ASSOCIATED BEAM, SAID PIN-SLOTCONNECTION PERMITTING EXPANSION AND CONTRACTION OF EACH OF SAID BEAMSINDEPENDENTLY OF ITS ASSOCIATED MOUNTING MEMBER AND SAID HOUSING.